Electronic device fabrication by conventional methods uses high resolution photolithography processes to form multilayer devices. These high-resolution processes require substantial investment in equipment to achieve precise layer-to-layer alignments on substrates that are relatively flat and rigid.
The processes and requirements of previous conventional photolithographic techniques are less successful when fabricating devices on flexible, stretchable substrates, especially when the substrate is a polymer. Fabrication of electronic devices such as thin film transistors on flexible substrates generally requires relaxed registration tolerance between device layers. In particular, polymer substrates may be prone to shrinkage or expansion due to thermal processing, and/or to absorption or desorption of water or other solvents, making layer to layer alignment difficult for conventional designs. Furthermore, conventional techniques are not generally amenable to manufacture using high-speed, roll-to-roll processes.
It is desirable to form transistors and/or other electronic devices on substrates that are flexible or stretchable. It is also desirable to fabricate such devices using low-cost roll-to-roll processing. The present invention fulfils these and other needs, and offers other advantages over the prior art.